Brake block



T. L. GATKE BRAKE BLOCK Filed July 24, 1931 Patented Oct. 8, 1935 UNITED STATES PATENT OFFICE BRAKE BLOCK Thomas L. Gatke, Oak Park, Ill. Application July 24, 1931, Serial No. 552,917

1 Claim.

The present invention has to do with brake blocks of the large molded composition type used on the shoes of heavy duty brakes, and is particularly concerned with the manner in which such blocks are fastened to the shoes.

Prior to this invention, it had been the practice to fasten the blocks to the shoes by means of socalled keeper plates, which plates were bolted to the shoes, usually in recesses formed in the faces of the latter, and were provided with outwardly offset clamping lips which engaged with the ends of the shoes in overlapped relation to relieved portions of the latter. That arrangement, aside from requiring the employment of rather elaborate attaching means, did not permit full coverage of the shoes by the blocks since space had to be left at the ends of the blocks to accommodate the attaching means.

The principal object of the invention is to pro vide a brake block of improved design which may be fastened securely to the ordinary keeper-type shoe without the necessity of employing keeper plates at the ends of the block; which is extreme-' 1y simple in construction, inexpensive to manufacture and easy to apply or remove; and which permits of substantially full coverage of the shoe without sacrificing either strength or security.

While the foregoing statements are indicative in a general way of the nature of the invention,

other objects and advantages will be apparent to those skilled in the art upon a full understanding of the construction of the improved brake block.

One form of the invention is presented herein by way of exemplification, but it will of course be appreciated that the invention is susceptible of embodiment in other somewhat modified structural forms coming equally within the scope of the appended claim.

In the accompanying drawing:

Fig. 1 is a side view of a brake shoe on which two brake blocks are secured in accordance with the invention;

Fig. 2 is a face view of the shoe and blocks shown in Fig. 1, with one end of one of the blocks broken away for clearness;

Fig. 3 is a perspective view of one of the blocks; and

Fig, 4 is a fragmentary longitudinal section through the shoe and blocks, taken on the line 4-! of Fig. 2.

The drawing shows a brake shoe I of ordinary construction, on which two brake blocks II are mounted. Since both of the blocks are the same, only one of them need be described in detail. As will be observed, the block I I is of uniform width and thickness and is arcuate in shape as'viewed on the back of the same with two cross ribs or lugs I4 which project into cross grooves I 5 formed in the shoe. The ribs I4 are preferably located adjacent the ends of the block, and the confronting sides I6 of the ribs are preferably beveled in order to fit contiguously against the opposed sides ll of the grooves and facilitate application and removal of the block. The sides I6 of the ribs on each block are disposed in planes which are nearly parallel to each other and each of said planes is normal to a plane which is tangential to the convex braking surface of the block at a point adjacent the opposite end of the latter. This arrangement provides a strong and solid anchorage for the blocks, in addition to the hereinafter hold-down means, regardless of the direction of rotation of the member being braked. The ribs I4 preferably bear snugly against the bottoms of the grooves and may be made slightly oversize and ground off to fit at the time of application.

At the locations of the ribs I4, the block is provided with bolt holes I8. The holes I8 extend not only through the block proper but through the additional thickness of the ribs I4 as well, and the outer ends of the holes I8 are counterbored a substantial distance at I9 to provide deep annular seats 20. a

The block II is secured to the shoe by means of bolts 2| which extend through the holes I8 into correspondingly located holes 22 in the shoe. The bolts 2| are provided with slotted heads 23 which bear against the seats at the bottoms of the counterbored portions of the holes I8, and are provided at their opposite ends with nuts 24. The under sides of the heads 23 of the bolts are shown as fiat, but they may be madeconical, in which case the annular seats 20 will also be made conical. The bolts 2|, when positioned and tightened up, clamp the block I I snugly against the shoe III, and the ribs l4 coact with the grooves I5 to resist endwise movement of the block on the shoe, thereby relieving the bolts 2| in large measure from the shearing stresses to which they would otherwise be subjected.

By providing the ribs I4 at the locations of the counterbored holes IS, the heads 23 of the attaching bolts 2| may be set in a substantial distance from the wearable friction face of the block without weakening the block at the points of attachment. The ribs M, in addition to reinforcing the countersunk holes It! for the bolts, also greatly strengthen the attaching connections by relieving the bolts from all shearing stresses.

I claim:

In a friction brake, the combination with a curved sho'e having transverse grooves in its convex face adjacent its ends and other transverse grooves in said face adjacent its center, which latter grooves are separated by a short section of said faceQof a pair of correspondingly curved friction blocks positioned. contiguously against said face in overlying relation to the center 'rooves, with the adjacent ends of the blocks overlapping said center section in substantially end-to-end relation to each other, transverse ribs on the concave backs of said blocks extended into ribs.

THOMAS L. GATKE. 

